Treatment of hydrocarbons



W. F. RITTMAN.

TREATMENT OF HYDROCARBONS.

APPLICATION FILED FEB. 5.1917.

1,330,008, I Patented Feb. 3,1920.

2 $HEETSSHEET l- WITNESSES W. F. RITTMAN.

TREATMENT OF HYDROCARBONS.

APPLICATION FILED FEB-5,1917.

Patented Feb. 3,1920.

z'suens-sman 2.

v '2 u u. E

wn'nzsszs INVENTOR Obi? - UNITED STATES PATENT oEEIoE.

WALTER F. RITTMAN, 0F PITTSBURGH, PENNSYLVANIA.

TREATMENT OF HYDROCARBONS.

Application filed February 5, 1917.

Y b 1/ whom it may concern:

. Be it known that I, \VALTER F. RITTMAN, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen ofthe United States, have invented or discovered certain new and useful Improvements in the Treatment of Hydrocarbons, of which improvements the following is a specification.

'In carrying out the process of cracking high-boilinghydrocarbon oils by subjecting them in the vapor state to conditions of temperature and pressure for a period of time adapted to produce the desired low-boiling by hydrocarbon, a new product is created which contains a larger percent of hydrocarbons of higher and lower or of higher or lower boiling points than in the original starting material. In other words, the original oil has been converted into an oil containing a much larger percentage of the lower boiling parts or fractions than were originally contained therein, This fact has made it necessary heretofore to condense the material coming from the cracking retorts and ithen handling the same in the conventional way as a new crude oil by sending it to receiving tanks and thence pumping it into a still where the product desired, as for example, gasolene or low boiling aromatic hydrocarbons, was separated from the balance of the crude material and the latter was then sent to receiving tanks, and later forced through the cracking retorts or direct to the cracking retorts or was otherwise disposed of. This method of operation necessitated a large amount of equipment in the way of receptacles, stills, pumps, lines, etc.

A very important item of expense was the heatnecessary for the distillation referred to above. In other words, a material with large quantities of heat was cooled off to atmospheric temperature, and after being cooled and stored, this same material was again heated sufficiently to distil off the desired constituents.

The invention described herein has for its object the combination of the process of decomposing or cracking heavy hydrocarbons into new molecular combinations of lighter and lower boiling hydrocarbons under suitably regulated conditions of time, temperature and pressure, such operation being carried out in'the vapor phase and a process of utilizing the heat stored in the products of the cracking reaction, for effecting a distil- Specification of Letters Patent.

Patented Feb. 3, 1920.

Serial No. 146,721.

lation of the desired lower boiling products from the heavier hydrocarbons Which can then, without further loss of heat, be cracked.

The present invention has for its purpose the utilization of heat present in the cracked oil as it leaves the cracking chamber, for purpose of separating the desired low boiling hydrocarbons thereby avoiding the necessity of applying fresh external heat. By carrying out the distillation or separation stage under a considerably reduced pressure or vacuum, the boiling temperatures of thehydrocarbon oils are reduced, thereby effecting the distillation of desired low boiling hydrocarbons with the heat carried from the retort by the vapors, etc. In other words, the large quantities of heat present in the cracked oil is made to do useful Work and instead of being a burden and expense, the same heat becomes a most decided asset.

It is well known that the boiling point of any given hydrocarbon decreases with the reduction of pressure, also that the hydrocarbons coming from the retort where they have been subjected to a temperature considerably in excess of -l00 (3., will retain much of this heat for a considerable length of time. The invention combines these recognized principles with the cracking system or operation referred to and thereby produces results whereby the original ma terial is progressively and uninterruptedly subjected to the action of the heat.

In the accompanying drawings forming a part of this specification, Figure 1 is a side elevation of a form of apparatus employed in the practice of the invention described herein; Fig. 2 is a plan view of the same; Fig. 3 illustrates a modification of the apparatus and is similar to Figs. 1 and 2. Fig. at is a plan of Fig. 3.

In the practice of the invention, it is preferred that a plurality of retorts 1 should have a valved connection with a common pipe or tube 2, so that the products from all the retorts may be discharged into such tube and conducted thence to branch pipes 3 which have independent valve connections 4 with the tanks 5 and 6. As the products escape from the retorts and flow along the connections to the tanks, there will be a considerable condensation and the vapors, condensate and carbon, will be discharged into said tanks. Only one of the tanks isconnected at a time with the retorts, such connection being controlled by valves 4. Gases and any vapors not condensed in the passage to the tanks, or while in such. tanks,

flow through valves 8 to a pipe 9 whereby along by the gases from the tanks and 6,

as described and claimed in applications filed February 5, 1917, Serial Numbers 146,724 and M6728. As soon as asufficient amount of liquid and carbon have accumu- .lated in one of the tanks, as 6, its connection with the retorts is closed and the other,

as 5, is connected to such retorts by shifting.

the respective valves 1 and at the same time the valve 8 of the charged tank is closed and the corresponding valve of the other tank is opened. The charged tank will now contain, as before stated, a mixture of hydrocarbon oils, some having a boiling point of above 30 degrees C. and others a very much higher boiling point, at atmospheric pressure. In order to effect a segregation of the low boiling hydrocarbons from the heavy oils, so as to permit of the latter being re-cracked or otherwise treated, use is made of the heat contained in the liquid in the tank 6 by reducing the pressure in such tank thereby lowering the boiling point to such an extent that gases condensable at or above 30 degrees C. will become again vaporized. To this end the mixing tanks 5 and 6 are connected to a suitable condenser 13 by the branched pipe 11, having valves 12 as clearly shown in Fig, 2, and the outlet from the condenser 13 is connected to a Vacuum pump 14where- 'by sufiic'ient vacuum .is formed in the tank 6. This pump dischargesinto a reservoir or storage tank 15. After the lower boiling oils have been withdrawn from the tanks as stated, the heavy higher boiling oils and carbon are discharged into a reservoir 7 or otherwise disposed of. i

The operation of the above described plant is necessarily intermittent in character for the reason that connection between the tank and the retorts must be closed before the foring necessary for the reaction desired in the retorts to maintain a super-atmospheric pressure therein. In order tomake the process continuous, a mixing tank 16 is interposed between the retorts and the vacuum tanks 5 and 6, etc. In the construction as shown in Figs. 3 and -.'l, the products of all the retorts flow into the mixing tank 16 and the gas and uncondensed vapors escape through the valve 8 and the pipe 9 to the absorbers 10. The liquid and solid material pass from the mixing chamber 16 through valves 17 which can be so adjusted as to maintain pressure in the mixing tank and the retorts, as is necessary for the desired reaction, and at the same time, a pressure below atmospheric can be maintained in the vacuum tanks 5 and 6 by the pump 14, as hereinbefore described. The operation of the apparatus shown in Figs. 3 aud t can be continued until heavy high-boiling hydrocarbons and carbon have accumulated in the tanks 5 or 6 to such an extent as make it desirable or necessary to effect removal of suc]. materials. These materials can either be discharged into a tank 7 (as in Fig. 1) from which the heavy hydrocarbons can be returned by any suitable means to the retorts for re-cracking, or if desired, the lower portions of the tanks 5 and 6 may be connected by a pipe 20 to the pump'21 whereby such heavy hydrocarbons can be drawn from the vacuum tank where segregation will occur, to the retorts.

I claim herein as my invention: 1. The rocess herein described which consists in su jecting high boiling hydrocarbon oils, in a vaporous state, to conditions of temperature and pressure for a .period of time adapted to produce the desired low boiling hydrocarbon, discharging the products of such treatn'ient into a suitable receptacle, reducing the pressure in said receptacle to permit of the vaporizing of the desired low boiling product from the liquid contained therein and condensing the vapors formed at such reduced pressures.

2. The process herein described which consists in subjecting high boilinghydrocarbon oils in a vaporous state toconditions of temperature and pressure 'for a period of time adapted to produce the desired low boiling hydrocarbon, discharging the products of such treatment into a suitable receptacle, permitting the gas to escape therefrom, and then reducin the pressure in said receptacle topermit of the vaporizing of low boiling products from the liquid contents, and condensing the vapors formed at such reduced pressures. I

3. In an apparatus for treating hydrocarbons, the combination of a retort, a receptacle for the reception of all the materialsformed in the retort, and means for reducing the pressure in said receptacle to permit of the vaporization of a portion of the material discharged into the receptacle.

4. In an apparatus for treating hydro-,.-

carbons, the combination of a retort, a receptacle for the reception of all the materials formed in the retort, means for reducing the pressure in said receptacle to permit of the vaporization of a portion of the material discharged into the receptacle, and means for condensing such vaporized portion.

In testimony whereof, I have hereunto set my hand.

WALTER F. RITTMAN. 

